Wild Onions in flower beds

Asked April 27, 2019, 11:00 AM EDT

How can I get rid of wild onions in my flower beds without killing good plants, We have tried digging them out to no vail. They are taking over many of our beds. They seem to spread so easily. We have heard don't try to pull them out so we don't do that,. I know if I use a stronger killer, that would work but it would also kill good plants. I have tried safe weed killers and they don't work. Thanks for your help.

Multnomah County Oregon wild onion

1 Response

Hi, and thank you for contacting Ask an Expert in regards to removing wild onions. Although ridding this perennial can be quite daunting and at times may seem futile however with constant diligence you will eventually eradicate them.

It is best to take steps to get rid of wild onions in the spring, before the plants have a chance to go to seed, or in the fall, which will weaken any surviving wild onion plants, making it more difficult for them to survive through the winter.

Killing wild onions starts with removing as much of the clump of wild onions as possible. Do not try to pull the clump of wild onions out of the ground. The small bulblets are designed to pull away from the mother plant when pulled, which leaves extra bulbs in the ground that will rapidly regrow. Instead, dig the clump out of the ground with a spade or a trowel. Throw the entire clump away. Do not shake excess dirt off back into the hole and do not compost. If you do, this will only respread the wild onion bulblets back into your garden.

After removing the wild onion plants, keep a close eye on the area and repeat the process if any new wild onions start to grow. Due to the hardy break-away bulblets, you can expect that they will grow back at least one time.

The next step to kill wild onions is to treat the area with either boiling water or a non-selective herbicide (like Round-up) – with a non-selective herbicide being the last resort. Both boiling water and non-selective herbicide will kill any plant it touches, so keep this in mind in regards to surrounding plants.

As you can see the overall concept in wild onion control is simple: kill existing plants before they can produce the next generation and ultimately you will deplete the soil of this weed. Wild onion control in practice is not quite so easy. Wild garlic control is difficult and will require planning and persistence by you. Nonetheless, its biology and predictable timing of new bulb formation gives you an opportunity for control.

Good luck, happy gardening, and again, thank you for contacting the Cooperative Extension Ask an Expert.